1. Field of the Invention
The present invention is related to an actuator, in particular, to an actuator with a position detecting mechanism.
2. Description of Related Art
It is known and common to use actuators on equipment such as electric medical beds, treadmills and wheelchairs for adjusting the elevations and tilting angles thereof. For medical emergencies and patient treatments, actuators with a quick-release mechanism allow quick adjustments on the medical beds such that the precious time for medical treatments can be significantly saved. The research of the present invention is based on such needs and actuators to provide further improvements thereto.
A conventional actuator typically comprises a main body, a transmission mechanism and a quick-release mechanism. The main body comprises an electric motor and a worm shaft extended outward from a center of the electric motor. The transmission mechanism comprises a lead screw shaft and a worm gear mounted on one end of the lead screw shaft and engaged in motion with the worm shaft. The quick-release mechanism comprises two cylindrical connecting members, in which one cylindrical connecting member is secured onto the lead screw shaft to rotate altogether therewith and another cylindrical connecting member is secured onto the worm gear to rotate altogether therewith. By using the engagement and disengagement between the cylindrical connecting members, the lead screw shaft and worm gear can be either brought to rotate altogether or disengaged from each other.
However, such conventional actuator is found to have the following drawbacks during its practical uses. As it is often of a complicated structure with various components, it can be difficult for assembly and installation. In addition, the material and manufacturing costs of the components are high, which significantly lowers its useful applications. Furthermore, since there is no corresponding detection being performed on the location of each one of the torque transmission components during the engagement and disengagement of the cylindrical connecting members, inaccurate positioning of the torque transmission components often occurs, which causes the torque transmission to be unable to engage properly for rotations and creates significant problems and inconvenience to the practical uses and operations thereof.